Hi Sergey, > What is correct way of adding specific versions of Haskell packages?
The user's manual has a section that demonstrates how to accomplish that: http://nixos.org/nixpkgs/manual/#how-to-override-package-versions-in-a-compiler-specific-package-set Other sections of the manual have useful information about this subject, too, so it might be worthwhile to read the whole chapter about Haskell. > Why do we have both, say, 'transformers' and 'transformers_0_3_1' but > only one (latest) version of many other pacakges, including > hackage-security? For every package, we ship the version suggested by LTS Haskell 7.x by default. If Hackage happens to have a newer version, too, then we add that as well. hackage-security is not part of LTS Haskell at all, so we have only the latest version. Best regards Peter _______________________________________________ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev